Magnetic disk drive systems are used to read and write information to and from magnetic disks. Typically, the disk is mounted on a spindle such that the disk can rotate to permit an electromagnetic head mounted on a movable arm positioned near the disk's surface to read or write information thereon.
During operation, the system moves the head to a desired radial position on the surface of the rotating disk where the head electromagnetically reads or writes data. Usually, the head is integrally mounted in a carrier called a "slider." A slider generally serves to mechanically support the head and any electrical connections between the head and the rest of the drive system.
Since the slider is aerodynamically shaped to glide over moving air, it generally maintains a uniform distance from the surface of the rotating disk, thereby preventing the head from undesirably contacting the disk.
Typically, a slider is formed with two parallel rails with a recessed area between the rails and with each rail having a ramp at one end. The surface of each rail that glides over the disk surface during operation is known as the "air-bearing surface."
A head is typically an electromagnetic device containing magnetic poles. These poles terminate on the air bearing surface and function to electromagnetically interact with the data contained in the magnetic disk.
According to the prior methods, a group of thin film sliders are fabricated from a single wafer that contains on its top face electromagnetic devices, i.e., heads, arranged in rows. Initially, single-row bars are sliced from a wafer, each bar comprising a row of units which can be processed into sliders having heads on their end faces. Each bar is then bonded to a fixture where the bar is then processed and separated into individual sliders.
During this process, it is critical to lap the bar to a desired thickness in order to achieve a desired throat height, i.e., the height of a pole above the pole widening point, for all the poles on the bar. The single-row bars tend to bow or bend, making it very difficult to attain this objective.
There is a need, therefore, to solve the bow problems associated with single-row bars so that sliders with desirable throat heights can be easily fabricated.